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DayNightTerminator[]

is a one-dimensional GeoGraphics primitive that represents the separation line between the halves of the Earth currently in daytime and nighttime.

DayNightTerminator[datespec]

represents the separation line between day and night for the specified date.

Details
Details and Options Details and Options
Examples  
Basic Examples  
Scope  
Properties & Relations  
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DayNightTerminator

DayNightTerminator[]

is a one-dimensional GeoGraphics primitive that represents the separation line between the halves of the Earth currently in daytime and nighttime.

DayNightTerminator[datespec]

represents the separation line between day and night for the specified date.

Details

  • datespec can be specified as a DateObject or a string that resolves to a date.
  • A date without explicit time zone is assumed to use $TimeZone.

Examples

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Basic Examples  (2)

Display the current terminator as a line:

Show the terminator line on the summer solstice using red lines to denote the Arctic and Antarctic Circles:

Use a different projection:

Scope  (3)

DayNightTerminator[] gives a plot for the current date and time:

Using Now explicitly gives the same result:

Illustrate changes in the terminator at monthly intervals:

Specify dates in other formats:

Properties & Relations  (2)

The terminator line separates the day and night hemispheres:

For a spherical model of the Earth, the terminator line is approximately a geo circle:

The true terminator and approximate terminator geo circle differ slightly when using an ellipsoidal model of the Earth:

Wolfram Research (2014), DayNightTerminator, Wolfram Language function, https://reference.wolfram.com/language/ref/DayNightTerminator.html.

Text

Wolfram Research (2014), DayNightTerminator, Wolfram Language function, https://reference.wolfram.com/language/ref/DayNightTerminator.html.

CMS

Wolfram Language. 2014. "DayNightTerminator." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/DayNightTerminator.html.

APA

Wolfram Language. (2014). DayNightTerminator. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/DayNightTerminator.html

BibTeX

@misc{reference.wolfram_2025_daynightterminator, author="Wolfram Research", title="{DayNightTerminator}", year="2014", howpublished="\url{https://reference.wolfram.com/language/ref/DayNightTerminator.html}", note=[Accessed: 04-August-2025]}

BibLaTeX

@online{reference.wolfram_2025_daynightterminator, organization={Wolfram Research}, title={DayNightTerminator}, year={2014}, url={https://reference.wolfram.com/language/ref/DayNightTerminator.html}, note=[Accessed: 04-August-2025]}